Phase meter



Nov. 16 1926. 1',607,526

R. M. .GILSON PHASE METER me d- Ost. 24. 1923 INVENTOR Patented Nov. 16, 1926.

UNITED STATES ROBERT M.'GILSON 01 PIT'ISBURGH, PENN'SYLVANIA, 11ss1enoamo VTHE NION 4 SWITGI-I & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION 01 PI EII\TNSYLVANIA.

1,607526 PATENT OFFICE.

PHASE METER.

pplication filed Oetober My i11vention relates to hase meters, that is, to apparatus for cletermining tl1e phase relation 01 two electro-motive forces.

I Will clescribe 0110 form 0tE-pllas0l11eer e111boclying 111y invention, anal Will t11an point out the novel features tl1ereol m claims.

111 tl1e accon1panying drawing, F1g. 1 1s a cliagrammatic vie1v showing one f01111 0f Phase 111eter embotlying my invention. Fig. 2 is a view pa1tly cliagrammat1c anal partly in elevation, showing 0110 f01111 of variable reactor s11itable f01 use in tl1e pl1ase meter 1lustratecl 111 Fig. 1. Fig. 3 is a vector diag1a111 showing the relatio11s of the electro- 1110tive f0rces in vatious arts of tl1e apparatus 01 Fig. 1. Si1nila1 reference characters reifer to sinnla1 Parts 111 eacl1 0f tl1e tl1ree views.

Referring first to Fig. 1, thapl1ase meter con1prises a pl1ase clisplacement n1easuring deviceA wl1ich .1'01' purposes of simplicity I shall te1111 a phase shifter, and an indicator D. Tl1e pl1ase sl1ifter A comprises an auto transformer having its coils divided into two winclings 10 und 11, by a terminal 5. As shown in tl1e drawing tl1e terminal 5 is ab tl1e electrical n1iclpoint 01 tl1e transforn1er. Tl1e reference character 13 desig- 11ates a variable non-incluctive resistance l1aving 0110 terminal connectecl with tl1e lower terminal 0f wincling 11. In similar manner a variable reactor 12 of eonstant re-' sistance l1as 0110 tern1inal connectecl with the 11pper terminal 0f wincling 10. The free terminals of reactor 12 and resistor 13 are connectecl, by means of vvi1e 3, with 0110 terminal 01: a wincling 6 0f inclicator D, the other terminal of winding 6 being connected with mid-point 5 01 the auto transformer'. Tl1e two winclings 10 ancl 11 are connected in series, by means of wires 1 ancl 2, across tl1e source of 0110 of tl1e electro-motive forces wl1ose pl1ase relation is to be n1easurecl.

The instantaneous voltages in phase shift- 01' A a1e illustratecl vectorially in Fig. 3. Assuming ancl e to 100 th'e electro-motive forces in winclings 10 and 11 respectively, their vector 511111 E will represent tl1e electron1otive force appliecl t0 wires 1 a11d 2. React01 12 ancl resiscor 13 are so proportioned tl1at wl1en tl1ese elements are all cut in, the electro-motive force 111 reactor 12 is represe11tecl by tl1e VGCEO1 6 the electro-motive force in resistor 13 by vector e and there- 24, 1923. Serial N0. 670,514.

fore the dlectromotive force 111 winding 6 of inclicator D is represented by vector 6 wl1icl1 is clisplacecl 90 110111 vect0rs 6 and e It is therefore clear tl1at With reactor 12 ancl re S1st0r 13 all cut 111 the electromotive force in WiIidil1g 6 is displaced 90 electrical degrees from the electro-motive force E across wires 1 and 2.

ancl the incluctance of reaotor 12 ls decreasecl, e Will lag behincl vect-o1 E by a decreasing angle. Vl1en the incluctance 0f reactor 12 is zero, 0 Wlll be in Phase 1vith'E. 'Sin1ila1ly if 1ea0t01 12 '1S kept constant at its n1aximun1 value and the value of reSistor 13 is 1eclucecl, ve0t0r 6 will lag bel1ind vector E by an increasing angle. As s11ming.the resistance 01 1eacfior 12 to be srnall 111 00111- parison wit-l1 its incluctance, then when the resistance of 13 15 zero, 6 will be approximately 180 out of phase with E. The 10* act0r 12 a11cl tl1e resistor 13 111aybe accu rately calibratecl so that theoperatorjcan detern1ine ab any filme the exact hase rela tion between tl1e electro-motive i0rces representecl by E and e One fo1m of variable reactor suitable f0r use in tl1e phase shilt'ter A con1prises, as shown in Fig. 2, a U-sl1apecl core 16 01' magnetizable material such as laminate-cl soft 11'011. A rotatable member 17, also 0f magn'etizable material is mounted between the legs of core 16 so as to complete the magnetic circuit. This n1embe1 ca'11'ies a pointer 17 co-operating With a fixed scale 20 for Teading the setting 0f the device. A Wincling 18 is proviclecl 011 member 17 a11cl a winding 19 is mounted 011 core 16, t-l1e two windings being connected in series. It is pla1n that by rotating member 17 the fluxes gene1'ated by the two windings 18 ancl 19 can be made to aid 01 to oppose each otl1er and thus regulate the reactance offered by the device, from a maximum t0 substantially zero.

In addition to wincling 6, indicator D c'on1prises a winding 7 ancl a pointer 9. Tl1e winding 7 is connecte-cl Wit-h ehe s01110e 01: the electro-motive force E which is to be compared with electro-motive force E sup plied t0 hase sl11fter A. This inclicator as here shown is an induction motor, the two windings 6 and 7 being the usual stator windings, and the pointer 9 being attacl1ecl to the rotor 20. Pointer 9 occupies a posi- If tl1e value of resistor 13 is keptconstant tion mid-vvaybetween the two st0p pins 9 on1y when the electro-motive f01ces supplied to windings 6 and 7 a1e exactly in hase. If the electro-motive force applied t0 Windiing 6 is 011t-pfphase With the electro=rnoive force *supphed to wmding 7, -pointer 9 swung in 0ne direction 01' the othr depend- 1ng 0n whether the electlo-mob1Ve force applied to wmdmg 6 ]eads 01 1ags.

T0 measur-e the phase relation 0f 5W0 elec. =tro-mot1ve forces oneelectro-mot1ve force E is connected with wires l and 22 andthec-ther niectr omotive force E is connecaed with winding ;7 ofindicator D. The reactor 12 und resistor 13 a1e then adjusted till th@ p01nten9 assumes a central pos1t1on thus 11'1- dicatmg :that ihe electro-rnotwe forces m windings 6 and 7 are in hase. Tne phaz;e

difference betweena und E can Ehen be 0bsenved vfrom the values of 13 and 12, und

-since 0 is in phase with the e-lectro-motive force in winding 7, this phase difirence is th e phase difference between the euechnmotive I"orces E and E.

Although I have barem shown und de scribed only one 'f01'11'1 and arangem :;t of

apparatus embo-dying my invention, it is understood that var1 ous changes und modn1- cations may be made berein xvithin the scope f.the appended claims withoutdeparting fro m .the spirit and sc0pe. of 1ny invention. Having thus described 1ny invention, what Ic1aim is:

1. In combination, two sources 0f electro- .111001Ve force, an auto transformer connected "he other s0urce and betxveen the mid-point ofsaid transformer and said point.

2. In combinat-ion, tw0 sources 0f alternating electromotive forees, an auto transformer connected With one said source, a variable -resistance connected with one terminal 0I" said transforrner, a variable renntance c0n11ected Wi'h the other terminal cf saidtransformer, a winding connected f1om an inter1nediate point 011 said transformer to the free ends 0f said.reactance and said resistance, a second winding connected with the second -said source, and means responsive t0 the hase of the electro-motive forces apvlied to said two windin s.

3. In combination, two sources 0i alternat1ng electromot1ve force, a wmd1ng counecbed with one said source, tvvo variable impedances of' difi'erent ower factors hav ing a common terminal ancl having their free terminals connected with the terminals respectively 0f the winding, and hase comparing means connected with the other source und betwveen said connnon t-erminal und an .1ntennechate pomt 011 sa1d Wind1ng. lntestnnony whereoi 1 afi1x my s1gnature.

ROBERT M. GILSON. 

